Loader for tractors



Sept-v 0, 1949. s. s. POKORNY LOADER FOR TRACTORS zsheets-snet 1 Filed Oct. 10, 1946 JWUMVM S.S.P0korny Sept. 20, 1949. s, s POKORNY LOADER FOR TRACTORS 2 Sheets-Sheet 2 Filed Oct. 10, 1946 v :J P S.S-.Pok0rny a, 3/

Patented Septzo', m

UNITED STAT S PATENT orrics Stephen S. Pokorny, Fort Dodge, Iowa Application October 10, 1'848,'Scrial No. 102,506

1 Claim. (Cl- 214-140) This invention relates to elevating and lowering means for farm implements. More particularly, it is an object of the invention to provide as an attachment for a tractor, a hoist which may be used for elevating or lowering an implement such as, for example, a sweep rake or scoop.

Loading mechanisms of the prior art for attachment to tractors and the like have usually been of a type having mechanism positioned high above the tractor itself so that it has been difficult to drive the tractor, with mechanism attached, under lower barn doorways and the like. Although some attempts have been made to construct loading mechanism which provide for low head-room yet these have had a further disadvantage in that they sacrificed ability to raise the scoop or rake to any considerable height and especially to heights at all approaching a vertical positioning of the main scoop-booms.

It is therefore an object of this invention to provide a material lifting mechanism for attachment to a tractor having both the advantages of low head-room and high elevating characteristics.

Another object ofthe invention resides in the provision of a mechanism as described employing hydraulic jacks which are more emcient, simpler and less likely to fail than winches, cables and other power lifting mechanisms.

A still further object of the invention resides in the provision of a lifting mechanism for attachment to a tractor having the scoop lifting arms thereof attached adjacent the rearward end of the tractor, having the hydraulic jacks thereof pivotally attached between the rearward end of the tractor and the lifting arms so that it is possible to raise and lower the lifting arms from a position in which the scoop is resting on the ground upwardly into a position approaching the vertical, in which the hydraulic jacks are approximately parallel to the lifting arms.

, Still further objects of the invention reside in the provision of a novel supporting plate for pivotally attaching the lifting arms and hydraulic jacks to the rear axle housing of a tractor, and in the provision of a bracing rod rigidly attached to the forward end of the tractor and to the lower end of said supporting plate.

A still further object of the invention resides in the provision of an apparatus for the purposes described, having a lesser number of parts and adapted to be more inexpensively manufactured than heretofore.

Other and still further objects and advantages of the invention will become apparent from the following description of a preferred embodiment thereof.

In the drawings:

Figure 1 is a side elevation of the material loading mechanism of this invention shown as 2 loading mechanism in its upward positions both being shown in dotted lines, certain parts of the framework as well as a part of the rear axle housing of the tractor being shown in full; .1

Figure 2 is a top plan view of the mechanism shown in Figure 1, a part of one of the lifting arms thereof being broken away to more clearly depict the hydraulic jack positioned therebeneath,

certain parts ofthe rear axle housing of the tractor being shown in full;

Figure 3 is a view in section taken along the line 3-3 of Figure 1; and

Figure 4 is a view in section taken along the line 4-4 of Figure 1.

The loading mechanism of this invention is generally indicated at it and is preferrbly intended for attachment to a tractor generally indicated at [2 in dotted lines.

The tractor I2 is preferably of a type provided with a square rear axle housing It and further provided with an oil pump unit adapted to operate fluid pressure operated attachments and having suitable valve means, not shown, for controlling the operation of such attachments.

The loading mechanism It includes a pair of lifting arms I6 arranged at opposite sides of the tractor l2. The rearward ends of the arms it are pivotally attached adjacent the rearward end of the tractor l2 and preferably by means of a pair of supporting plates It. The supporting plates 18 are preferably in a vertically disposed \position and are preferably provided each with a pair of horizontally extending ears 20 at the upper ends thereof to which the flattened rearward ends 23 of the lifting arms l8 are pivotally attached by means-of a pair of pins 22. The supporting plates It may be secured in any suitable manner'to the rear axle housing of the tractor l2, however, when the tractor I2 is one of the type having a square rear axle housing It surrounding its rear axle 24, then the supporting plate It is positionedflush against the forward side of Means are provided for raising the lifting arms l6 and such means includes a pair of hydraulic jacks 32 having their cylinders pivotally attached to the opposite sides of the rearward end of the tractor l2. Preferably, each of the cylinders 32 are provided with a flattened tab 3| on the rearward end thereof which are attached by means attached to a tractor, the tractor as well as the so of a pin 33 to a pair of horizontally extending ears 34 which size in turn attached to the lower end of the corresponding supporting plate It, the supporting plate It being of such a length as to extend both above and below the rear axle 24 of the tractor I2. The jack cylinders 32 are ate tached to a source of hydraulic pressure such as an oil pump unit, not shown, the interconnection between the jack cylinders 32 and the oil pump unit being made by a pair of flexible conduits 36.

The jacks 32 are each provided with pistons 38 and piston rods 40, the outward ends of the piston rods 40 being each pivotally attached to the lower side and adjacent the front end of the lifting arms It, the attachment being preferably made by means of a pair of triangular connection plates 42 which are suitably attached to the under side of the lifting arms it, the piston rods 58, since at times when the scoop 58 is loaded, its

' center of gravity will be normally forwardly of the pivotal connection formed by the bolt 88. The operator of the tractor may cause the rearward motion of the lever 12 by pulling-upon a line 14 fttachfzd to an eyelet 16 in the upper end 01' the ever i The lower end of the lever 12 is pivotally at tached by means of a pin 78 between a pair of fora brace rod 46 is employed, being rigidly attached to a pair of trunnion plates 48 which are disposed at either side of the forward end of the tractor l2, the trunnion plates being secured to the frame 50 of the tractor by means of a pair of bolts 52. The

means of a nut 56 and the rearward ends of I the brace rods 46 are attached to the lower end of the supporting plate l8 in any suitable manner.

The distance between the pivotal mountings of the rearward end of the lifting arms l6 and the rearward ends of the hydraulic jacks 32 is preferably such as to form a triangle between the lifting arms l6 and their corresponding hydraulic jacks and supporting plates, the angle formed between the supporting plates i8 and their corresponding hydraulic jacks 32 is preferably an angle approaching 90 degrees or greater at times when the lifting arms l6 are in their lowest position. At times when the lifting arms iii are in raised position, the angle formed between the supporting plates l8 and the corresponding hydraulic jacks 32 becomes more and more acute until at times when the lifting arms [6 are in their uppermost position, preferably the hydraulic jacks 32 will be substantially parallel with the lifting arms [6.

A scoop 58 having tines 60 is pivotally mounted by means of a pair of bolts 62 disposed at either side thereof to the outer ends of the lifting arms it.

Means are provided for controlling the position of the scoop with respect to the lifting arms 16 and such means includes a cross bar 64 rigidly at.-' tached to each of the lifting arms l6 closely adjacent the rearward wall 66 of the scoop 58. The rearward wall 66 is provided with a lock 68 secured thereto of U-shape in top plan view and a latch 10 adapted to be positionable within the- U- shaped lock 68, the latch 10 being so attached to a lever 12 that at times when the lever 12 is in a forward position, the latch 10 will engage the lock 68, preventing dumping movements of the scoop 58 and at such times as the lever'l2 is in a rearward position, the latch ID will be freed from the lock 68, permitting a dumping motion of thescoop wardly extending ears 80, the said ears being attached, to the forward side of the cross piece 64.

In operation, it will be seen that the loading mechanism of this invention will not reduce the headroom of the tractor l2 and that the tractor, with the present invention attached thereto, will be free to pass under low entry ways such as barn doors and thelike. It will be further seen that the advantages of low head-room are attained without sacrifice of operating qualities since the new loading mechanism is so constructed that the scoop thereof may be raised from an on-theground position upwardly into a position in which the lifting arms it are approaching the vertical.

From the foregoing description, it is thought to be obvious that a loading mechanism constructed in accordance with my invention is particularly well adapted for use by reason of the convenience and facility with which it may be assembled and operated, and it will also be obvious that my invention is susceptible of some change and modification without departing from the principles and spirit thereof and for this reason,

v I do not wish to be understood as limiting myself to the precise arrangement and formation of the several parts herein shown in carrying out my invention in practice, except as claimed;

I claim:

In a loading mechanism for attachment to a tractor of the type having a source of hydraulic pressure: a vertical support secured to the rear axle housing of said tractor; a lifting arm disposed at one side of said tractor, the rearward end of said arm being pivotally attached to said support, the forward end of said lifting arm extending forwardly of the tractor; a. hydraulic jack disposed below said lifting arm, said jack being pivotally secured at one of its ends to said support directly beneath the pivotal attachment between said arm and said support, the other end of said jack being pivotally secured to said lifting arm at a point between the ends of the latter; a conduit for interconnecting said hydraulic cylinder and said source of hydraulic pressure; and a tie rod attached to the lower end of said support and to the forward end of said tractor to relieve twisting strain on said tractor between said rear axle housing and the forward portions of said tractor.

STEPHEN S. POKORNY.

REFERENCES crrEn The following referencesare of record in the file of this patent:

UNITED STATES PATENTS 

